Beethoven’s Opus 5, No. 1 in F, Opus 102, No. 1 in C and Opus 69 in A, may be labeled cello sonatas, but that’s not to imply that the piano is a mere supporting player to the featured instrument.

In her collaboration with veteran cellist Lynn Harrell Friday in a Mainly Mozart Festival program at the Neurosciences Auditorium, McDermott was more than just an equal partner. She did much of the driving in a lively program highlighted by a particularly energetic rendering of the A Major sonata, an undisputed masterwork.

Beethoven would have appreciated McDermott’s approach, given his seeming lack of reticence as a pianist. In these three pieces (along with two others, which the pair will perform Saturday in the festival’s closing concert), Beethoven essentially invented the 19th-century cello sonata. For much of the 18th century, the cello was still struggling to escape its role as part of the Baroque continuo (relegated to playing the bass line along with the harpsichord). Neither Mozart nor Haydn even bothered writing a cello sonata.

So it’s hardly surprising the F Major, written when the Beethoven was 26, starts tentatively, soon glances back at Mozart in the nature of its primary theme and then moves assertively into the future.

The three works provided a fascinating look at Beethoven’s progress, with the A Major Sonata, written around the time he wrote his Fifth Symphony, showing a composer at the height of his powers, and then the highly concentrated C Major Sonata showing the mature Beethoven’s more reflective tendencies.

There wasn’t much reflection in McDermott and Harrell’s readings. In all three sonatas, they kept the music moving forward. But at times they were overbearing, especially as they didn’t calibrate their playing to the room. The auditorium’s acoustics are stunningly accurate, but also unforgiving.

When McDermott was at her most energetic, she sounded harsh. Harrell, especially at the top of his range, too often sounded strident, like an aging tenor who has lost some of the warmth in his voice.

If it wasn’t an evening for subtlety, it was an evening for celebration as the two musicians enjoyed each other’s company and especially in the A major, seemed in the moment.

When it was over, Harrell gave McDermott a well-deserved kiss. That likely wouldn’t have happened to an accompanist.